Methods of and apparatus for unwinding a helically wound elongated body

ABSTRACT

A mandrel having a telephone cord coiled thereon is mounted vertically and rotatably with one end of the cord attached to a spindle mounted rotatably on a reciprocally movable carriage. The carriage is moved relative to the mandrel to uncoil the cord and successive sections of the cord are moved axially horizontally and generally perpendicular to a stationary plate positioned between the mandrel and the carriage at the same time the axis of the cord is moved transversely vertically so that portions of the cord adjacent to the other end thereof are moved into, and pulled through, a slot formed in the plate. Simultaneously, the ends of the cord are twistingly rotated relative to each other to reverse the direction of the helical coil. As the other end of the cord is disengaged from the mandrel, the last few convolutions of the cord spring together and expand radially on the mandrel side of the plate until the other end of the cord engages a pair of spaced pins attached to the mandrel-side of the plate on opposite sides of the slot. The pins retain the last few convolutions of the cord on the mandrel-side of the plate, and the cord is maintained strung between the spindle and the plate to facilitate removal by an operator.

[54] METHODS OF AND APPARATUS FOR UNWINDING A HELICALLY WOUND ELONGATEDBODY [72] Inventor: Edwin C. Hardesty, Perry Hall, Md.

[73] Assignee: Western Electric Company, Incorporated,

- New York, NY.

[22] Filed: Aug.31, 1970 [21] Appl.No.: 68,376

l/l966 Howell, .lr ..l 8/l9 Primary Examiner- Lowell A. LarsonAttorney-W. M. Kain, R. P. Miller and Don P. Bush [5 7] ABSTRACT Amandrel having a telephone cord coiled thereon is mounted vertically androtatably with one end of the cord attached to a spindle mountedrotatably on a reciprocally movable carriage. The carriage is movedrelative to the mandrel to uncoil the cord and successive sections ofthe cord are moved axially horizontally and generally perpendicular to astationary plate positioned between the mandrel and the carriage at thesame time the axis of the cord is moved transversely vertically so thatportions of the cord adjacent to the other end thereof are moved into,and pulled through, a slot formed in the plate. Simultaneous1y, the endsof the cord are twistingly rotated relative to each other to reverse thedirection of the helical coil. As the other end of the cord isdisengaged from the mandrel, the last few convolutions of the cordspring together and expand radially on the mandrel side of the plateuntil the other end of the cord engages a pair of spaced pins attachedto the mandrel-side of the plate on opposite sides of the slot. The pinsretain the last few convolutions of the cord on the mandrel-side of theplate, and the cord is maintained Strung between the spindle and theplate to facilitate removal by an operator.

15 Claims, 4 Drawing Figures BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates to methods of and apparatus forunwinding a helically wound elongated resilient body, and, moreparticularly, to methods of and apparatus for unwinding and reversingthe pitch of a retractile cord wound helically on a mandrel.

2. Description of the Prior Art Electrical retractile cords, which arereferred to in the art as spring cords, are widely used in thecommunications industry and in connection with various electricalapplicances. One example of an electrical retractile cord, hereinafterreferred to as a spring cord, is the spring cord utilized to connect thehandset of a telephone instrument to the telephone base. The spring cordis manufactured with a major portion thereof in the form of a compacthelical coil, which may be extended by a slight tension and which willreturn to the compact form when the tension is relieved.

In a preferred process of manufacturing spring cords for telephoneinstruments, a predetermined length of jacketed, multiconductor cordageis wound in a helix along the length of a rotating and longitudinallymoving mandrel, preferably as disclosed in U.S. Pat. No. 3,024,497issued on Mar. 13, 1962 to E. C. l-lardesty and D. L.- Myers Asdisclosed in that patent, the cordage is first cut to a predeterminedlength, and is then tipped and banded and wound subsequently on amandrel. After the winding operation, the trailing end of the cordage isclamped to the mandrel, and then the mandrel with the helically coiledcordage clamped thereto is placed in an oven and heat treated.

In one type of preferred cordage, the jacketing material comprises aplasticized polyvinyl-chloride composition having 4 elastic properties,as disclosed in U.S. Pat. No. 3,037,068 issued on May 29, 1962 to H. L.Wessel. The cord is heated on the mandrel to a temperature above thesoftening point of the polyvinyl-chloride composition, to relievestrains in the jacketing material and to set the cord in a helical-coiland is then cooled to room temperature. After cooling, the heattreatedcord is removed from the mandrel and the pitch of the helical coil isreversed in order to provide a spring cord having retractility, asdisclosed in U.S. Pat. No. 2,920,348 issued on Jan. 12, 1960 to E. L.Franke, Jr.

As disclosed in the U.S. Pat. No. 2,920,348, an apparatus may include apair of spaced endless members each having a plurality of opposedworkholders secured thereon, between pairs of which partially formedspring cords are secured. As the endless members are moved insynchronism, the opposed holders are rotated in opposite directions toreverse the helices of the coil of each cord and to impart an overtwistthereto. An endless chain with fingers thereon serves to impart tensionto the spring cord to prevent knotting and kinking thereof.Subsequently, the direction of rotation of the holders is reversed toremove a predetermined amount of the overtwist from the cords.

A new and improved method of and apparatus for stretching a spring cordby controlled, varying amounts during helix-reversing and overtwistingoperations to produce a finished spring cord is disclosed in U.S. Pat.No. 3,087,199, issued on Apr. 30, 1963 to E. L. Franke, Jr. et al.

Apparatus is also commercially available for unwinding a spring cordfrom a mandrel on which the cord has been wound helically andheat-treated and for simultaneously reversing the pitch of the helicesof the coil of the cord.

An apparatus for removing the heat-treated spring cord from the mandreland for reversing the pitch of the helices of the coil includes a framehaving facilities for mounting vertically rotatably a plurality ofmandrels in a spaced parallel ar ray. A reciprocally movable carriagehaving a plurality of spindles rotatably mounted thereon is supportedfrom the frame with each of the spindles aligned with an associated oneof the mandrels.

In operation, an operator positions a full complement of the mandrels inthe frame, each of the mandrels having a retractile cord' woundhelically thereon, and clamps one free end of each of the spring cordsto the associated aligned one of the spindles. The operator thencontrols the operation of the apparatus to move the carriage linearlyaway from the mandrels to unwind the spring cords from the associatedmandrels. Simultaneously, the spindles are rotated in such a manner asto reverse the pitch of the helix of the spring cords being unwound fromthe mandrels. Moreover, a predetermined amount of overtwist is impartedto the cords to induce additional torque to the cords which is of helpin distributing evenly the forces imparted to the cord throughout theentire length of the cord.

As the carriage reaches the end of the path of travel in a firstdirection away from the mandrels, the trailing end of each of the springcords is pulled free of the mandrels. The release of the trailing endsof the spring cords from the mandrels permits the inherent spring-likecharacteristics of the cords to cause the convolutions of the cords tospring together toward the ends of the spring cords still held in thereversing spindles at which time the overtwist is released from thecords. As a result of the predetermined amount of overtwist imparted tothe cord, the convolutions of the finished product are more uniform andmore compact, i.e. smaller in diameter. Also, the movement of thecarriage is changed to a second direction opposite to the firstdirection to return the carriage to an initial position in the vicinityof the operator and with the unwound reversed cords dangling from thespindles.

Manufacturing economies dictate the simultaneous reversal of more thanone spring cord in each apparatus which represents considerableinvestment. No problems are apparent when using an apparatus of theabove-described type for reversing relatively short spring cords, e.g. 4feet in length. However, when using the above-described apparatus forreversing longer spring cords, problems may occur. In order to unwindall of the convolutions from the mandrel, it becomes necessary to inducesubstantial additional twist into the cords in the same amount ofcarriage travel.

When the trailing ends of the longer cords are pulled from theassociated mandrels and the convolutions spring together, the length ofthe cords may cause the cords to become entangled thus requiringadditional operator time to disentangle the cords before removing thecords from the spindles for transportation to a subsequent work station.Moreover, the additional twist imparted to the spring cords generallycauses the spring cords to knot up and kink which results in a loss ofthe normal helical shape of the cords and the accompanying successivelyordered convolutions which also require additional operator attention tocorrect.

Even if an apparatus having a longer bed and longer length of carriagetravel was used for the reverse recoiling of the longer variety ofspring cords, entanglement may still occur when the trailing ends of thecords are released from the mandrels and the convolutions springtogether.

Still further, manufacturing economies may be realized by using higherspeeds for the carriage travel and the rotation of the spindles. Thesemodifications could result in knotting of the individual cords andentanglement of the associated cords when using such an apparatus forthe reverse recoiling of even the shorter spring cords.

One solution would be to compartmentize the individual cords by usingseparating partitions between the adjacent cords. The partitionsovercome the problem of entanglement of adjacent ones of the cords, butthe knotting-up of the individual cords may still occur.

The problems described may be surmounted by devising methods of andapparatus for maintaining the helical shape of the spring cords with theconvolutions of each of the cords in a successive ordered array afterthe cords have been unwound from the associated mandrels andreverserecoiled to permit an operator to remove the cords from theapparatus without the necessity of disentangling and/or unknotting thecords.

If the other end of each of the cords were engaged after the other endsare unwound from the associated ones of the mandrels, then, not onlywould the problem of entanglement of adjacent cords and knotting ofindividual cords be solved, but, also, provisions could be made forremoving a predetermined amount of the overtwist. The ability to removea predetermined amount of the overtwist permits control over theuniformity and degree of compactness of the convolutions of the cord.

At the end of the path of travel in the first direction, the directionof rotation of the spindles is reversed to remove the overtwist and thecarriage is moved in a second direction opposite to the first directionto return the carriage to an initial position. The reverse rotation toremove the overtwist may be accomplished while the carriage isstationary at the end of the path of travel in the first direction orwhile the carriage is being returned to the initial position.

SUMMARY OF THE INVENTION It is therefore another object of thisinvention to provide methods of and apparatus for unwinding a helicallywound elongated body in such a manner as to secure the trailing end ofthe elongated body when the elongated body is completely unwound.

It is therefore another object of this invention to provide methods ofand apparatus for unwinding spring cords wound individually on mandrelsand for reversing the pitch of the helices of the spring cords withfacilities for preventing the entanglement of adjacent ones of aplurality of the cords as the cords are unwound from the mandrels andfor preventing knotting of individual ones of the cords.

A method of unwinding a helically wound elongatedbody which illustratescertain features of the present invention, may include the steps ofholding one end of the elongated body, causing relative movement betweenthe one end and unwound portions of the elongated body to unwind theresilient body and move the axis of successive unwound portionstransverse of a confining device, and engaging unwound portions of theelongated body adjacent the trailing other end of the elongated bodyprior to the elongated body being completely unwound to secure thetrailing end of the elongated body when the elongated body is completelyunwound.

Apparatus illustrating certain features of the invention may includefacilities for mounting rotatably a workholder having an elongated bodycoiled helically thereon with provisions for holding one end of thecoiled elongated body in a rotatably mounted spindle and causingrelative movement between the one end and the unwound portions of theelongated body to unwind the body from the workholder with provisionsfor engaging only portions of the unwound portions of the elongated bodyprior to the elongated body being unwound completely to secure the otherend of the elongated body when the elongated body is completely unwound.

Other objects and features of the present invention will be more readilyunderstood in the following detailed description of specific embodimentthereof when read in conjunction with the accompanying drawings inwhich:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of anapparatus which embodies certain principles of this invention whichincludes a reciprocally movable carriage having a plurality of rotatablymounted spindles thereon for moving away from plural rotatably mountedmandrels having cords coiled thereon to unwind the cords from themandrels and move portions of the cords adjacent the trailing endsthereof through associated ones of a plurality of slots formed in aplate positioned between the mandrels and the carriage.

FIG. 2 is an elevational view of the apparatus of FIG. 1 and showing oneof the spring cords wound on a mandrel being unwound therefrom atsuccessive stages of the unwinding operation.

' FIG. 3 is an enlarged detailed view of a portion of the plate anddepicting one of the slots with a pair of spaced pins attached to andprojecting laterally of the plate on the mandrel side thereof with theunwinding of the cord having proceeded to where portions of the cordadjacent the trailing end thereof on the mandrel are about to be movedtransversely into and through the slot while being pulled axiallygenerally perpendicularly of the plate by an associated one of thespindles on the carriage.

FIG. 4 is an enlarged detail view of the slot and portion of plate shownin FIG. 3 at a later instant of time when the trailing end of the cordhad been unwound from the mandrel and the last few convolutions of thecord are engaged with one of the pins and are retained on themandrel-side of the plate to maintain the cord strung between the plateand the carriage.

DETAILED DESCRIPTION Referring now to FIG. 1, there is shown anapparatus 10, which is used to carry out the principles of the method ofthe invention for unwinding a helically wound elongated body, and, inparticular, for unwinding and reversing a plurality of retractile orspring cords 11-11, each of the cords being wound helically on a mandrel12. The details of construction of the mandrel 12 together with adescription of the structure of the cord 11 and the coiling of the cordon the mandrel 12 may be found by referring to US. Pat. No. 3,024,497,issued on Mar. 13, 1962 to E. C. Hardesty and D. L. Myers.

Each of the spring cords 11-11 has a central section con sisting of aplurality of closely-packed helical turns or convolutions 13-13 (seealso FIG. 3) of a jacketed cordage 14 and a pair of end portions 16-16.The jacketed cordage 14 includes a core composed of a plurality ofindividually insulated conductors (not shown) preferably tinselconductors, positioned parallel to each other and which may be enclosedin a paper tape. The jacketing material is preferably extruded over thepaper-covered core to form a long, straight length of the jacketedcordage 14. Portions of the jacketed cordage are then wound into helicalform, being cut to length either after, or preferably before, thehelix-winding operation.

A portion of the jacket adjacent to each of the end portions 16-16 ofthe spring cord 11 is stripped from the conductors, after which thespring cord is terminated by a tipping and banding operation. Thestripping, tipping and banding of the cord 11 may be performed after thehelix-winding operations; however, a predetermined straight length ofthe jacketed cordage 14 may be cut and the ends stripped, tipped andbanded previous to coiling the helical form. This latter sequence ofoperations is preferred since it is easier to cut, strip, tip and bandthe cordage before coiling rather than after, and such sequence is moresusceptible to mass-production assembly techniques.

After a predetermined length of the jacketed cordage 14 has been woundhelically on one of the mandrels 12-12 by a coiling operation such asthe coiling operation described in the above-mentioned U.S. Pat. No.3,024,497, the cord 11 is conveyed to a heat-treating oven (not shown)to set the cord in a helical shape. The apparatus 10 is adapted toreceive and hold a plurality of the mandrels 12-12, each of the mandrelshaving a heat-set retractile cord 11 wound helically thereon inpreparation for unwinding the cord from the associated mandrel, andreversing the helices of the coil.

As can best be seen in FIG. 1, the apparatus 10 includes a base 21having a plurality of spaced, rotary bearing blocks 22-22 at one endthereof, each of the bearing blocks being mounted in a support 23. Thebearing block supports 23-23, further designated 23a to 23d, are mountedon the frame 21 and are spaced transversely across the base in a steppedfashion from the foreground of the apparatus 10 to the rear thereof, asviewed in FIG. 1. Each of the bearing blocks 22- 22 is adapted toreceive one end of one of the mandrels 12- 12 and to hold the mandrel sothat the mandrel may be turned rotatably therein. The other end of eachof the mandrels 12- 12 is received in an associated one of a pluralityof slots 24- 24 cut in a top portion 26 of a bracket 27 that is attachedto the one end of the base 21.

The unwinding of the cords 11-11 from associated ones of the mandrels12-12 involves the imparting of forces to the cords and the associatedmandrels. The mandrels 12-12 are subjected to forces directed transverseof the longitudinal axes of the mandrels and generally parallel to thelongitudinal axis of the base 21. These forces tend to pivot themandrels 12-12 within the associated ones of the bearing blocks 22-22 topull the top ends thereof out of the associated ones of the slots 24-24.

The slots 24-24 are cut in the top portion 26 of the bracket 27 so thatthe mandrels 12-12 are held securely in a vertical position parallel toone another as is shown in FIG. 1 during the unwinding of the cords11-11 therefrom. Accordingly,

the slots 24-24 are cut angularly of the top portion 24 with a nestingopening 28 formed at the interior end of each of the slots. The topportions of the mandrels 12-12 are received in associated ones of theslots 24-24 within the nesting portions 28-28 during the unwinding ofthe cords 11-11. With this arrangement, the forces exerted on themandrels 12-12 are oblique of the slots 24-24 and do not pull themandrels out of the associated ones of the slots.

In order exert pulling forces to ones of the end portions 16-16 of thecords 11-11 to unwind the cords from the associated ones of the mandrels12-12, a carriage 31 is mounted for reciprocal movement in a pair ofspaced ways 32-32 on the base 21. .A plurality of spindles 33-33,designated further 33a-33d, are mounted rotatably on the carriage 31with each of the spindles associated with one of the bearing blocksupports 23a-23d respectively.

The spindles 33a-33d are mounted on the carriage 31 in an ascendingarrangement beginning in the foreground of the carriage as viewed inFIG. 1 to correspond to the stepped arrangement of the bearing blocksupports 23a-23d, respective ly. The arrangement of the bearing blocksupports 23a-23d and associated ones of the spindles 33a33d isadvantageous from the standpoint of bio-mechanics in that thearrangement facilitates operator insertion and removal of the mandrels12- 12 and the attachment of the end portions 16-16 of the cords ll-llto the spindles.

Each of the spindles 33-33 has a bifurcated end 34 having upturned andportions 36-36 through which the end portion 16 of an associated cord 11is passed, and a U-shaped portion 27 (see FIGS. 1 and 2) spaced from theupturned end portions for receiving one of the free end portions 16-16of the cord to secure the cord to the spindle. It should also beobserved that the apparatus may accommodate cords 11-11 having free endportions 16-16 or having end portions which have been terminated. Thespindles 33-33 are driven insynchronism by an interconnected drive (notshown) which is controlled by an operator.

The spindles 33-33 are turned in a first rotary direction,counterclockwise as shown in FIG. 1, to twistingly rotate the ends ofthe cords 11-11 relative to each other to reverse the convolutions 13-13of the cords as the carriage 31 is moved linearly away from the mandrels12-12 to simultaneously unwind the cords from the associated mandrels.Moreover, the relative rotation of the end portions 16-16 of each of thecords may be continued to impart a precise amount of overtwist to thecords to form additional helices of the reversed direction in the coiledportions thereof.

Sufficient torsional energy must be imparted from the spindles 33a-33dto the cords l-l-ll on the associated mandrels 12-12 to reverse the lastfew ones of the convolutions 13- 13 on each of the cords adjacent thetrailing ones of the end portions 16-16 thereof. A predetermined amountof overtwist is imparted to each of the cords 11-11 by formingadditional helices of the reversed direction in the coiled portion. Theovertwist which is induced in the cords 11-11 by controlling therotation of the spindles 33a-33d insures that an amount of energy isstored in the cords 11-11 so that when the last few ones of theconvolutions 13-13 are unwound from the mandrels, the pitch of thosehelices will be reversed.

Subsequently the overtwist is removed from the spring cords 11-11. Theconvolutions13-13 in the cords 11-11 after the overtwist has beenremoved are of substantially uniform diameter, pitch and spacing and aremore compact, i.e., of a smaller diameter than would have been achievedwithout the overtwist. The removal of the overtwist is accomplished withthe shorter spring cords 11-11 when the cord ends are released from themandrels 12-12 and ones of the end portions 16-16 dangle from theassociated spindles 33a-33.

The portions of the apparatus 10 described hereinsofar may be used tounwind and reverse simultaneously the helical coil of a plurality ofspring cords 11-11 which are relatively short, e.g. 4 feet. When thecarriage 31 has been moved relative to the rotatably mounted mandrels12-12, from an initial position to approximately the end of a path oftravel in the first direction, the shorter cords 11-11 will have beenunwound completely from the associated ones of the mandrels with onefree end portion 16 of each of the cords held in the bifurcated end 34of the associated one of the spindles 33a33d, and with the other freeend portion 16 of each of the cords dangling therefrom.

The extent of movement of the carriage 31 is limited by the length ofthe base 21, which may be dictated by manufacturing floor spaceconsiderations. In the case of longer cords 11-11, the cords may not beunwound from the associated ones of the mandrels 12-12 in the .same orslightly greater length of travel and with the same speed of rotation ofthe spindles 33-33. In these situations, the spindles 33-33 are turnedrotatably at a higher rate of speed to impart more overtwist into thelonger cords 11-11 than with the shorter cords during the linearmovement of the carriage 31 in the first direction to shorten theeffective length of the cords that are to be unwound.

With the longer cords 11-11, when the trailing end portions 16-16 areunwound from the associated ones of the mandrels 16-16, the cords willknot and kink up individually and tangle with adjacent cords. Therefore,provisions must be made to secure the trailing end portions 16-16 as thetrailing end portions are unwound from the mandrels 12-12 and to rotatethe spindles 33-33 a predetermined amount in a 'the base 21 intermediatethe mandrels 12-12 and the carriage 31. The plate 42 is positioned sothat as successive sections of the cords 11-11 are unwound from themandrels 12-12, the successive sections are moved axially, generallyperpendicular of the plate.

Moreover, the plate 42 is formed with a plurality of slots 43-43,designated further 43a-43d, cut vertically therein and aligned withassociated ones of the bearing block supports 2311-23 and associatedones of the spindles 33a-33d. Each of the slots 43a43d has a flaredentrance 44 to facilitate the movement of portions of a cord 11 into theslot. The plate 42 is shaped so that adjacent ones of the slots 43a-43dare ascending from the forefront of the base 21, as viewed in FIG. 1, tothe rear portion thereof to correspond to the aligned ascending supports2311-2311 and spindles 33a-33d.

the other end of the path of travel of the carriage 31 so that as thecarriage is moved in the first direction toward the other end of thepath of travel, the axes of the cords 11-11 are moved transversely ofthe plate. Portions of the cord 11 adjacent the end thereof are movedinto and pulled through the associated one of the slots 43a43d (see FIG.3). Then, as the end of each of the cords 11-11 is unwound from theassociated one of the mandrels 12-12 successive sections engage thebottom walls of the associated slots 43-43.

The confining device 41 has provisions for securing the last fewconvolutions adjacent the other end of each of the cords 11-11 when thecords are unwound completely from the mandrels 12-12. As can best beseen in FIG. 3, a pair of spaced pins 46-46 are attached to the plate 42adjacent each one of the slots 43a43d. The pins 46-46 project laterallyof the plate 42 back toward the associated one of the mandrels 12-12 andare spaced apart a distance greater than the width of the slot 43.

One of the pins 46-46 of each pair of the pins is attached to the plate42 on one side of the associated slot 43 and the other one of each pairof pins on the other side of the associated slot, both pins being on themandrel-side of the plate 42. Also, as can best be seen in FIGS. 2 and3, each pair of the pins 46-46 is attached to the plate 42 spanning theassociated one of the slots 43a43d with the pins spaced vertically abovethe bottom of the associated slot.

The pins 46-46 serve to prevent the sections of each of the cords 11-11adjacent the end portions 16-16 thereof from being pulled through theassociated ones of the slots 43-43 in the plate 42. As the trailing endportions 16-16 of the cords ll-ll are unwound from the mandrels 12-12,the last few convolutions 13-13 adjacent the end portion thereof expandand spring together on the mandrel-side of the plate 42. As the carriage31 is further advanced in the first direction, the sections of each ofthe cords 11-11 adjacent the end portion 16 thereof tend to turn about acenter within the associated slot 43. As the trailing end portion 16turns, either the last few convolutions 13-13 or the trailing endportion engages the pins 46-46 to prevent further unscrewing of theremainder of the convolutions of the cord 11 through the slot. (See FIG.4 which illustrates the condition where ones of the last fewconvolutions 13-13 engage one of the pins 46-46.) The engagement of thetrailing end portion 16 or ones of the last few convolutions of thehelical coil of each of the cords 11-11 with the pins 46-46 secures theend portion of each of the cords 11-11 to the confining device 41 afterthe carriage 31 has reached the end of the path of travel in the firstdirection, and prevents the trailing end portions from becomingdisengaged with the confining device.

OPERATION In carrying out the method of the invention with the apparatuswhich embodies the principles of the invention, the operator loads theapparatus with a plurality of the mandrels 12-12 on each of which hasbeen wound helically, and heat set, a spring cord 11. The operatorpositions the lower end of one ofthe mandrels 12-12 with a cord 11 woundhelically thereon in one of the bearing blocks 22-22 and moves pivotallythe topmost portion of the mandrel into the associated one of the slots24a-24d in the top portion 26 of the bracket 27.

After the operator has positioned a loaded mandrel 12, the operatorgrasps the top free end portion 16 of the cord 11 and threads the topfree end portion through the bifurcated end 34 of the aligned associatedspindle 33, and turns the free end portion under the U-shaped portion 37to secure the free end portion to the spindle. The operator positionsadditional ones of the mandrels 12-12 in the remaining ones of thebearings 22-22 and slots 24-24 and attaches similarly the free endportions 16- 16 of the cords 11-11 coiled thereon to the associated onesof the spindles 33a33d.

At this time, when all of the mandrels 12-12 are loaded and the free endportions 16-16 of the cords 11-11 coiled thereon are secured to theassociated ones of the spindles 33-33, the carriage 31 is at one end ofthe path of travel adjacent the plate 42 toward the left end of the base21, as viewed in FIG. 1.

Then the operator controls the operation of the carriage 31 to move thecarriage from the initial position at the one end of the path of traveladjacent the plate 42, in the first direction, to the right as viewed inFIG. 1, to the other end of the path of travel. Simultaneously, theoperator controls the operation of the apparatus 10 to rotate thespindles 33a-33d in the first rotary direction to reverse the pitch ofthe convolutions 13-13 of the coils as the cords 11-11 are unwound fromassociated ones of the mandrels 12-12.

During the unwinding and reversing of the cords ll-ll, each of the cordsassumes a tight, extended form having a substantially long lay (seeFIGS. 1-3). The tight twisted form of each of the cords 11-11 serves todistribute the torque along the cords between the spindles and themandrels and facilitates the transmission of torsional energy fromassociated ones of the spindles 33-33 to the associated mandrels 12- 12.

As each of the cords ll-ll is unwound from associated ones of themandrels 12-12, successive sections thereof are moved axially generallyperpendicularly of the plate 42. Moreover, the axis of each of the cordsll-ll is moved transversely of the plate 42. Then, as the axis of eachof the cords 11-11 becomes more and more inclined (see FIG. 2), portionsof each of the cords adjacent the trailing end portion 16 thereof aremoved into the associated flared entrance 44 and into the associatedslot 43.

Also, it should be observed that only segments of the cords 11-11adjacent the trailing ends thereof are moved into and through theassociated ones of the slots 43a43d. In this way, contact of the cords11-11, with the walls of the slots 43043 is kept at a minimum whileproviding for catching and securing the trailing ends 16-16 of the cordsto hold the cords strung out between the associated ones of the spindles33a-33 and the mandrels 12-12.

The apparatus 10 is controlled to induce the predetermined overtwistinto the cords 11-11 to impart sufficient torsional energy to the cordson the mandrels 12-12 to reverse the last few convolutions 13-13 of eachof the cords adjacent the trailing end portions 16-16 thereof. Care mustbe taken to insure the transmittal of the additional energy from thespindles 32-32 to the mandrels 12-12 when successive sections of thecords 11-11 are moved through associated ones of the slots 43-43. Theconfining device 41 is designed so as not to interfere with thetransmittal of the torsional energy up to the mandrels 12-12 which isrequired to reverse the of the last few ones of the convolutions 13-13.Hence, the slots 43-43 are dimensioned to be greater than the diameterof the cordage 14 and sufficiently wide to pass the tight long lay cordwithout inhibiting the distribution of the torque thcrealong.

As can best be seen in FIG. 2, as the last few convolutions 13-13 of thecord coils are unwound from the associated ones of the mandrels 12-12,the positioning of the plate 42, with respect to the mandrels and thelength of travel of the carriage 31, is such that the axis of each ofthe cords extending between the associated mandrel and spindle 33, asviewed with the apparatus in front elevation, is not linear but isangled at the associated slot 43. Successive sections near the other endof each of the cords 11-11 are moved toward and then in engagement withthe bottom wall of the associated slot 43.

The friction engagement of only segments of each of the cords 11-11 withthe bottom wall of the associated one of the slots 43a43d exerts a dragon the cords and permits the last few ones of the convolutions 13-13thereof to expand to the original diameter thereof. The distance betweenthe plate 42 and the mandrel 12-12 is determined to insure that theexpansion of the last few ones of the convolutions 13-13 of each of thecords occurs before the last few ones of the convolutions engage theconfining device 41.

After the ones of the last few convolutions 13-13 of the cords 11-11 areunwound and have expanded, the trailing end portion 16 or the ones ofthe last few convolutions engage one of the associated pair of pins416-46 (see FIG. 4). This prevents sections of the cords adjacent theends thereof from turning about the associated ones of the slots43a-43d. As a result, the last few convolutions 13-13 of each of thecords- 11-11 are held on the mandrel-side of the plate 42, with thecords 11-11 strung out between the associated slots 43a-43d and theassociated spindles 33a-33d, while the overtwist is removed from thecords.

Then, the overtwist is removed from the cords 11-11 with theconvolutions 13-13 remaining in the cord after the overtwist has beenremoved being of substantially uniform diameter, pitch and spacing. Thisis accomplished with the shorter spring cords 11-11 when the cord endsare released from the mandrels 12-12 and dangle from the associatedspindles 33a-33d. With the longer cords 11-11, after the trailing endsof the cords 11-11 are secured in the confining device 41, the spindles33-33 are rotated a predetermined amount in a direction opposite of thefirst rotary direction to remove the overtwist from the cords 11-11.

Should the operator release the cords 11-11 while the cords are in anextended condition before the overtwist has been removed therefrom, thecords will knot and kink up individually and tangle with adjacent cords.Then the movement of the carriage 31 is controlled to move the carriagein a second direction opposite to the first direction to return thecarriage to the initial position where the operator removes the cords11-11 from the apparatus 10. The removal of the overtwist is preferablyaccomplished simultaneous with the movement of the carriage in thesecond direction, but could be accomplished priorly thereto.

Then, when the carriage 31 has been returned to the initial position,the plurality of cords 11-11 are strung out in a generally catenaryconfiguration between the plate 42 and as sociated ones of the spindles33a-33d to facilitate removal by the operator. By securing the other endof each of the cords 11-11 as the cords are unwound completely from themandrels 12-12, and continuing to hold both ends of each cord tomaintain the cord strung out either in a taut or in a catenary position,entanglement of adjacent ones of the cords is avoided as well asknotting or kinking of individual ones of the cords. Moreover, thisarrangement permits control of the removal of the overtwist.

It is to be understood that the above-described arrangements are simplyillustrative of the principles of the invention. Other arrangements maybe devised by those skilled in the art which will embody the principlesof the invention and fall within the spirit and scope thereof.

lclaim:

1. A method of unwinding a helically wound elongated body, whichincludes the steps of:

holding one end of the elongated body;

causing relative movement between the one end and the wound portion ofthe helically wound elongated body to unwind the elongated body whilemoving successive unwound portions thereof transverse of a confiningdevice; and

engaging unwound portions of the elongated body adjacent to the otherend of the elongated body prior to the elongated body being unwound tosecure the other end of the elongated body when the elongated body isunwound completely.

2. A method of unwinding a helically wound elongated body, whichincludes the steps of:

holding one end of the elongated body;

causing relative movement between the one end and the wound portion ofthe helically wound elongated body to unwind the elongated body to movesuccessive portions thereof axially generally transversely of aconfining device while moving simultaneously the longitudinal axis ofthe elongated body transversely of the confining device; and

engaging only a segment of the unwound portions of the elongated bodyadjacent to the other end of the elongated body prior to the elongatedbody being unwound to secure the other end of the elongated body whenthe elongated body is unwound completely.

3. A method of unwinding and reversing the pitch of a helically woundelongated body, which includes the steps of:

holding one end of the elongated body;

twistingly rotating the ends of the helically wound elongated bodyrelative to each other to reverse the direction of the coil thereof;

causing relative movement between the one end and the wound portion ofthe helically wound body to unwind the elongated body while movingsuccessive unwound portions thereof transverse of a confining device;and

engaging unwound portions of the elongated body adjacent to the otherend of the elongated body prior to the elongated body being unwound tosecure the other end of the elongated body when the elongated body isunwound completely.

4. A method of unwinding and reversing the pitch of a helically woundelongated body, which includes the steps of:

holding one end of the elongated body; twistingly rotating the ends ofthe helically wound elongated body relative to each other to reverse thedirection of the coil thereof;

causing relative movement between the one end and the wound portion ofthe helically wound body to unwind the elongated body and movesuccessive unwound portions thereof axially generally transversely of aconfining device while moving simultaneously the longitudinal axis ofthe elongated body transversely of the confining device; and

engaging only a segment of the unwound portions of the elongated bodyadjacent to the other end of the elongated body prior to the elongatedbody being unwound to secure the other end of the elongated body whenthe elongated body is unwound completely.

5. A method of unwinding and reversing the pitch of a retratile cord,wound helically on a mandrel, which includes the steps of:

gripping one end of the cord;

twistingly rotating the ends of the cord relative to each other toreverse the direction of the helical coil;

pulling the one end of the cord from an initial position axially in afirst direction to unwind the cord from the mandrel and advancesuccessive unwound portions thereof generally perpendicular of a slottedguide while moving simultaneously the axis of the cord transversely ofthe guide to pull unwound portions of the cord adjacent the other endthereof through the slotted guide; and

engaging only a segment of the unwound portions of the cord adjacent theother end of the cord in the vicinity of the initial position after thelast few convolutions are un-' wound from the mandrel to secure theother end of the cord when the cord is completelyunwound.

6. A method of unwinding and reversing the pitch of a cord woundhelically on a mandrel, which includes the steps of:

gripping one end of the cord;

twistingly rotating the ends of the cord in a first rotary directionrelative to each other to reverse the pitch of the helical coil andthereafter overtwisting the cord by continuing the relative rotation ofthe ends to form additional convolutions of the reversed direction inthe coiled portion;

pulling the one end of the cord in a first direction and through apredetermined distance to unwind the cord to move successive portionsthereof axially generally perpendicular of a slotted guide while movingsimultaneously the axis of a cord transversely of the guide to pullportions of the cord adjacent the other end thereof through the slottedguide;

engaging only a segment of the unwound portions of the cord adjacent tothe other end thereof and prior to the cord being unwound completelyfrom the mandrel to retain ones of the last few convolutions of the cordin enmeans mounted on the confining means for engaging unwound portionsof the elongated body adjacent to the other end of elongated bodysubsequent to the elongated body being completely unwound to secure theother end gagement with the guide and maintain the coil axis lonf he lngat d body when the elongated body is gitudinal of the helices of thecord in a taut essentially completely unwound.

linear configuration with adjacent ones of the helices 10, An apparatusfor simultaneously unwinding and being spaced apart; and reversing thepitch of an elongated resilient body wound helitwistingly rotating theends of the cord in a second rotary all on aworkholder, which comprises:

direction opposite to the first rotary direction to remove means forholding one end of the elongated resilient body;

the overtwist from the cord while moving the other end of means f t i il tati g the end of the resilient body the cord in a second lineardirection opposite to the first i h respect to h other t eve the pitchof th linear direction until the coil axis is substantially catenary ilib d in cohhghratloh with adjacent ones ofthe helices abutting 15 meansfor causing relative movement between the one end one another.

and the unwound portions of the resilient body to unwind the resilientbody from the workholder and pull the other end from the mandrel; andmeans for engaging only a segment of the unwound portions of theresilient body adjacent the other end of the resilient 7. A method ofreversing the pitch of a plurality of spring cords formed in helicalcoils on mandrels, which includes the steps of:

mounting rotatably and individually the mandrels;

clamping one end of each of the cords in a rotatably mounted spindle;

twistingly rotating in a first rotary direction the ends of each of thecords relative to each other to reverse the direction of the coils andthereafter over-twisting the spring cords by continuing the relativerotation of the ends to form additional helices of the reverseddirection in the coiled portron;

pulling the one end of each of the cords in a first linear direction tounwind successive ones of the convolutions body prior to the elongatedbody being completely unwound from the workholder to secure the otherend of the resilient body when the resilient body is completely unwoundfrom the workholder.

11. An apparatus for simultaneously unwinding and reversing the pitch ofan elongated resilient body wound helically on a workholder, whichcomprises:

means for holding one end of the elongated resilient body; means fortwistingly rotating the ends of the resilient body from the associatedmandrel and advance successive secl h s gfg i each other to reverse thepltch of the i ofthe: col-cl ax'any generally perpendlcular to a platemeans for causihg relative movement between the one end hallmg pluralityof slots cut therem each of and unwound portions of the resilient bodyto move such 2 iff the h f f an i g q cessive unwound portions axiallygenerally transverse of one 0 6 8pm w 16 moving aneous y e axis theworkholder while moving simultaneously the axis of f each of thecords.transversely of the plate to pull porthe body generally transverseof the workholder; and thons of t 3 t i other end thereofthrough meansfor engaging unwound portions of the elongated t e associate oneo t e sots; engaging portions of each of the cords adjacent to the other ig gxf g 3 2 82:; it? t s fi s g :33 ends thereof as the other end of eachof the cords 1s 40 p g y g p y from the workholder to secure the otherend of the elonwithdrawn from the mandrel to retain ones of the last fewconvolutions of each of the cords on the mandrel-side of the plate andmaintain the convolutions of each of the cords spaced apart and strungout between the plate and the associated spindle with the longitudinalaxis of the coil being essentially in a taut extended configuration; and

twistingly rotating in a second rotary direction opposite to the firstrotary direction the ends of the cords relative to and the wound portionof the helically wound resilient body to unwind the elongated body tomove successive portions thereof axially generally of the confiningmeans, while moving simultaneously the axis of the body transverse ofthe confining means; and

reversing the pitch of an elongated resilient body wound helically on amandrel, which comprises:

means for mounting rotatably the mandrel;

means for gripping one end of the resilient body;

means for advancing the one end of the resilient body in a firstdirection through a predetermined distance to uneach other to remove theovertwist from the cords while simultaneously moving the other ends ofthe cords in a wmd the mandrel; I Second linear direction opposite tothe first linear means for twistingly rotating in a first rotarydirection the direction to have the longitudinal axis of the coil assumea ends of the heslhem body f l respect to each othet to retractedgenerally catenary configuration reverse the pitch of the resilient bodyand subsequent to 8. An apparatus for unwinding a helically woundelongated h one h havlhg behhadvahced thfohgh the predeterhody whichcomprises; mined distance to twistingly rotateun a second rotary meansfor holding one end fth elongated body; direction OPPOSIIC IhC firstrotary directlon the ends to means for causing relative movement betweenthe one end remove the vPrtW15tthetetrm and the wound portion f thehelically wound elongated means for engaging the last few convolutionsof the resilient b d to i d h elongated b d d body ad acent the otherend thereof as the other end of means for engaging only a segment of theunwound portions the res l ent body is withdrawn from the mandrel tohold of the elongated body adjacent to the other end of the thel'eslhhht y Strung between the PP theahs and elongated body prior to theelongated body being unthe engaging means with the convolutions in anextended wound to secure the other end of the l ted b d condition and alongitudinal axis of the helical coil when the elongated body iscompletely unwound. generally taut; and 9. An apparatus for unwinding ahelically wound elongated means 0 ng th h r end of the body in a secondbody, which includes: direction opposite to the first direction with theconvolumeans for holding one end of the elongated resilient body; tionsretracted and the longitudinal axis generally in a means for confiningportions of the elongated body; catenary configuration. means forcausing relative movement between the one end 13. An apparatus forreversing the pitch of a retractile cord wound helically on a mandrel,which comprises:

a frame;

means for mounting rotatably the mandrel on the frame;

means mounted reciprocally on the frame for holding one end of aretractile cord;

between the means for mounting rotatably the mandrel and the holdingmeans, the plate having a slot cut therein and aligned with the axis ofthe cord as strung between the holding means and the mandrel;

the cord having successive sections thereof moved axially generallyperpendicular of the plate and transverse of the axis of the mandrel,the axis of the cord being moved transversely of the plate to moveportions of the cord adjacent the other end thereof into and through theslot; and

means attached to the plate for engaging ones of the last fewconvolutions of the cord as the otherend of the cord is unwound from themandrel and for retaining the last few convolutions of the cord on themandrel-side of the plate to maintain the cord strung between the plateand the holding means.

14. An apparatus for unwinding and reversing the pitch of i the helicesof a plurality of retractile cords, each of the retractile cords beingwound helically on a mandrel, which comprises:

a frame;

means for mounting rotatably the mandrels on the frame;

a carriage mounted reciprocally on the frame;

a plurality of spindles rotatably mounted on the carriage, each of thespindles adapted to hold one end of the one of the retractile cords,further each of the spindles aligned with one of the mandrels;

means for moving the carriage from an initial position in a firstdirection relative to the mandrels to unwind the cords from theassociated mandrels;

means responsive to the movement of the carriage in the first directionfor rotating the spindles in a first rotary direction to reverse thepitch of the helices of the cords and for overtwisting the cords to formadditional helices of the reversed direction in the coiled portion;

a stationary plate attached to the frame and positioned between themeans for mounting rotatably the mandrels and the carriage, the platehaving a plurality slots cut therein, each of the slots aligned with theaxis of an associated one of the cords as strung between the spindlesand the mandrels;

the cords having successive sections thereof moved axially generallyperpendicular of the plate and transverse of the axis of the associatedmandrels, the axes of the cords being moved transversely of the plate tomove portions of the cords adjacent the other ends thereof into andthrough the associated ones of the slots;

means attached to the plate for engaging portions of the cords adjacentthe other ends thereof as the other ends of the cords are unwound fromthe associated ones of the mandrels and for retaining at least fewconvolutions of the cords on the mandrel-side of the plate to maintainthe cords strung between the plate and the associated ones of thespindles;

means for moving the carriage in a second direction opposite to thefirst direction to return the carriage to the in H4 itial position; and

means responsive to the movement of the carriage in the second directionfor rotating the spindles in a second rotary direction opposite to thefirst rotary direction to remove the overtwist from the cords.

15. An apparatus for unwinding and reversing the pitch of the helices ofa plurality of retractile cords, each of the retractile cords beingwound helically on a mandrel, which comprises:

a frame;

means for mounting rotatably the mandrels on the frame;

a carria e mounted reciprocally on the frame; a plur ity of spindlesrotatab y mounted on the carriage,

each of the spindles adapted to hold one end of one of the retractilecords, further each of the spindles aligned with one of the mandrels;

means for moving the carriage from an initial position in a firstdirection relative to the mandrels to unwind the cords from theassociated mandrels;

means responsive to the movement of the carriage in the first directionfor rotating the spindles in a first rotary direction to reverse thepitch of the helices of the cords and for overtwisting the cords to formadditional helices of the reversed direction in the coiled portion;

a stationary plate attached to the frame and positioned between themeans for mounting rotatably the mandrels and the carriage, the platehaving a plurality of slots cut therein, each of the slots aligned withthe axis of an as sociated one of the cords as strung between thespindles and the mandrels;

the cords having successive sections thereof moved axially generallyperpendicular of the plate and transverse of the axis of the associatedmandrels, the axes of the cords being moved transversely of the plate tomove portions of the cords adjacent the other ends thereof into andthrough the associated one of the slots;

the cords having still further successive sections thereof adjacent theother ends thereof engage the bottom walls of the associated slots asthe trailing end portions are unwound from the mandrels to permit thelast few convolutions to expand to an original diameter;

a plurality of pairs of pins attached to the plate and extend inglaterally therefrom toward the means for mounting the mandrels, eachpair of the pins associated with one of the slots, one of each pair ofthe pins being on one side of the associated slot and the other one ofthe pair on the otheside of the associated slot, further each pair ofthe pins being spaced above the bottom of the associated slot;

each pair of the pins engaging portions of the cords adjacent the otherends thereof after the last few convolutions thereof have expanded onthe mandrel side of the plate for retaining the last few convolutions ofthe cords on the mandrel-side of the plate to maintain the cords strungbetween the plate and the associated ones of the spindles;

means for moving the carriage in a second direction opposite to thefirst direction to return the carriage to the initial position; and

means responsive to the movement of the carriage in the second directionfor rotating the spindles in a second rotary direction opposite to thefirst rotary direction to remove the overtwist from the cords.

L-566-PT UNITED STATES PATENT OFFICE CERTIFIC TE OF CORRECTlON PatentNo.3,656,516 I t Dated Avril 18. m7? j EDWIN C. vHARDESTY It iscertifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

,m In the specification, Column'S, line 25, following "order" insert-to-. Column 5, line H7, "27" should read --37-- Column 6, line 12, "33"should read -*33d--. Column 6, line 61,- "23a-23" should read --23a23d-Column 8, line 38, Ba-H3" should read -'+3al3d--. Column 8, line #1, "33a-33" should read -i-33a33d--. Column .9, line 52,

-"I claim:" should read --What is claimed is"-. Column 10,

line 73, "a" should read --the--. Column 12, line 17, "mandrel" shouldread -workholder-. Column 13, line 30, delete second "the", Column 13,line 57', "at least" should read -the last--.

Column l line H7 "otheside" should read --otherside-.

Signed and sealed this 14th day of January 1975.

(SEAL) Attest: V I

GIBSON JR. -c. MARSHALL DANN 2232:8515 Officer Commissioner of Patents

1. A method of unwinding a helically wound elongated body, whichincludes the steps of: holding one end of the elongated body; causingrelative movement between the one end and the wound portion of thehelically wound elongated body to unwind the elongated body while movingsuccessive unwound portions thereof transverse of a confining device;and engaging unwound portions of the elongated body adjacent to theother end of the elongated body prior to the elongated body beingunwound to secure the other end of the elongated body when the elongatedbody is unwound completely.
 2. A method of unwinding a helically woundelongated body, which includes the steps of: holding one end of theelongated body; causing relative movement between the one end and thewound portion of the helically wound elongated body to unwind theelongated body to move successive portions thereof axially generallytransversely of a confining device while moving simultaneously thelongitudinal axis of the elongated body transversely of the confiningdevice; and engaging only a segment of the unwound portions of theelongated body adjacent to the other end of the elongatEd body prior tothe elongated body being unwound to secure the other end of theelongated body when the elongated body is unwound completely.
 3. Amethod of unwinding and reversing the pitch of a helically woundelongated body, which includes the steps of: holding one end of theelongated body; twistingly rotating the ends of the helically woundelongated body relative to each other to reverse the direction of thecoil thereof; causing relative movement between the one end and thewound portion of the helically wound body to unwind the elongated bodywhile moving successive unwound portions thereof transverse of aconfining device; and engaging unwound portions of the elongated bodyadjacent to the other end of the elongated body prior to the elongatedbody being unwound to secure the other end of the elongated body whenthe elongated body is unwound completely.
 4. A method of unwinding andreversing the pitch of a helically wound elongated body, which includesthe steps of: holding one end of the elongated body; twistingly rotatingthe ends of the helically wound elongated body relative to each other toreverse the direction of the coil thereof; causing relative movementbetween the one end and the wound portion of the helically wound body tounwind the elongated body and move successive unwound portions thereofaxially generally transversely of a confining device while movingsimultaneously the longitudinal axis of the elongated body transverselyof the confining device; and engaging only a segment of the unwoundportions of the elongated body adjacent to the other end of theelongated body prior to the elongated body being unwound to secure theother end of the elongated body when the elongated body is unwoundcompletely.
 5. A method of unwinding and reversing the pitch of aretratile cord, wound helically on a mandrel, which includes the stepsof: gripping one end of the cord; twistingly rotating the ends of thecord relative to each other to reverse the direction of the helicalcoil; pulling the one end of the cord from an initial position axiallyin a first direction to unwind the cord from the mandrel and advancesuccessive unwound portions thereof generally perpendicular of a slottedguide while moving simultaneously the axis of the cord transversely ofthe guide to pull unwound portions of the cord adjacent the other endthereof through the slotted guide; and engaging only a segment of theunwound portions of the cord adjacent the other end of the cord in thevicinity of the initial position after the last few convolutions areunwound from the mandrel to secure the other end of the cord when thecord is completely unwound.
 6. A method of unwinding and reversing thepitch of a cord wound helically on a mandrel, which includes the stepsof: gripping one end of the cord; twistingly rotating the ends of thecord in a first rotary direction relative to each other to reverse thepitch of the helical coil and thereafter overtwisting the cord bycontinuing the relative rotation of the ends to form additionalconvolutions of the reversed direction in the coiled portion; pullingthe one end of the cord in a first direction and through a predetermineddistance to unwind the cord to move successive portions thereof axiallygenerally perpendicular of a slotted guide while moving simultaneouslythe axis of a cord transversely of the guide to pull portions of thecord adjacent the other end thereof through the slotted guide; engagingonly a segment of the unwound portions of the cord adjacent to the otherend thereof and prior to the cord being unwound completely from themandrel to retain ones of the last few convolutions of the cord inengagement with the guide and maintain the coil axis longitudinal of thehelices of the cord in a taut essentially linear configuration withadjacent ones of the helices being spaced apart; and twistingly rotatingthe ends of the cord in a secoNd rotary direction opposite to the firstrotary direction to remove the overtwist from the cord while moving theother end of the cord in a second linear direction opposite to the firstlinear direction until the coil axis is substantially catenary inconfiguration with adjacent ones of the helices abutting one another. 7.A method of reversing the pitch of a plurality of spring cords formed inhelical coils on mandrels, which includes the steps of: mountingrotatably and individually the mandrels; clamping one end of each of thecords in a rotatably mounted spindle; twistingly rotating in a firstrotary direction the ends of each of the cords relative to each other toreverse the direction of the coils and thereafter over-twisting thespring cords by continuing the relative rotation of the ends to formadditional helices of the reversed direction in the coiled portion;pulling the one end of each of the cords in a first linear direction tounwind successive ones of the convolutions from the associated mandreland advance successive sections of the cord axially generallyperpendicular to a plate having a plurality of slots cut therein, eachof the slots being aligned with one of the mandrels and an associatedone of the spindles, while moving simultaneously the axis of each of thecords transversely of the plate to pull portions of the cord adjacentthe other end thereof through the associated one of the slots; engagingportions of each of the cords adjacent to the other ends thereof as theother end of each of the cords is withdrawn from the mandrel to retainones of the last few convolutions of each of the cords on themandrel-side of the plate and maintain the convolutions of each of thecords spaced apart and strung out between the plate and the associatedspindle with the longitudinal axis of the coil being essentially in ataut extended configuration; and twistingly rotating in a second rotarydirection opposite to the first rotary direction the ends of the cordsrelative to each other to remove the overtwist from the cords whilesimultaneously moving the other ends of the cords in a second lineardirection opposite to the first linear direction to have thelongitudinal axis of the coil assume a retracted generally catenaryconfiguration.
 8. An apparatus for unwinding a helically wound elongatedbody, which comprises: means for holding one end of the elongated body;means for causing relative movement between the one end and the woundportion of the helically wound elongated body to unwind the elongatedbody; and means for engaging only a segment of the unwound portions ofthe elongated body adjacent to the other end of the elongated body priorto the elongated body being unwound to secure the other end of theelongated body when the elongated body is completely unwound.
 9. Anapparatus for unwinding a helically wound elongated body, whichincludes: means for holding one end of the elongated resilient body;means for confining portions of the elongated body; means for causingrelative movement between the one end and the wound portion of thehelically wound resilient body to unwind the elongated body to movesuccessive portions thereof axially generally of the confining means,while moving simultaneously the axis of the body transverse of theconfining means; and means mounted on the confining means for engagingunwound portions of the elongated body adjacent to the other end ofelongated body subsequent to the elongated body being completely unwoundto secure the other end of the elongated body when the elongated body iscompletely unwound.
 10. An apparatus for simultaneously unwinding andreversing the pitch of an elongated resilient body wound helically on aworkholder, which comprises: means for holding one end of the elongatedresilient body; means for twistingly rotating the ends of the resilientbody with respect to each other to reverse the pitch of the resilieNtbody; means for causing relative movement between the one end and theunwound portions of the resilient body to unwind the resilient body fromthe workholder and pull the other end from the mandrel; and means forengaging only a segment of the unwound portions of the resilient bodyadjacent the other end of the resilient body prior to the elongated bodybeing completely unwound from the workholder to secure the other end ofthe resilient body when the resilient body is completely unwound fromthe workholder.
 11. An apparatus for simultaneously unwinding andreversing the pitch of an elongated resilient body wound helically on aworkholder, which comprises: means for holding one end of the elongatedresilient body; means for twistingly rotating the ends of the resilientbody with respect to each other to reverse the pitch of the resilientbody; means for causing relative movement between the one end andunwound portions of the resilient body to move successive unwoundportions axially generally transverse of the workholder while movingsimultaneously the axis of the body generally transverse of theworkholder; and means for engaging unwound portions of the elongatedbody adjacent to the other end of the elongated body prior to theelongated body being unwound completely from the workholder to securethe other end of the elongated body when the elongated body iscompletely unwound.
 12. An apparatus for simultaneously unwinding andreversing the pitch of an elongated resilient body wound helically on amandrel, which comprises: means for mounting rotatably the mandrel;means for gripping one end of the resilient body; means for advancingthe one end of the resilient body in a first direction through apredetermined distance to unwind the resilient body from the mandrel;means for twistingly rotating in a first rotary direction the ends ofthe resilient body with respect to each other to reverse the pitch ofthe resilient body and subsequent to the one end having been advancedthrough the predetermined distance to twistingly rotate in a secondrotary direction opposite the first rotary direction the ends to removethe overtwist therefrom; means for engaging the last few convolutions ofthe resilient body adjacent the other end thereof as the other end ofthe resilient body is withdrawn from the mandrel to hold the resilientbody strung between the gripping means and the engaging means with theconvolutions in an extended condition and a longitudinal axis of thehelical coil generally taut; and means for moving the other end of thebody in a second direction opposite to the first direction with theconvolutions retracted and the longitudinal axis generally in a catenaryconfiguration.
 13. An apparatus for reversing the pitch of a retractilecord wound helically on a mandrel, which comprises: a frame; means formounting rotatably the mandrel on the frame; means mounted reciprocallyon the frame for holding one end of a retractile cord; means for causingrelative movement between the holding means and the means for mountingrotatably the mandrel and for rotating the holding means to unwind theconvolutions of the cord from the mandrel and to reverse the pitch ofthe cord; a stationary plate attached to the frame and positionedbetween the means for mounting rotatably the mandrel and the holdingmeans, the plate having a slot cut therein and aligned with the axis ofthe cord as strung between the holding means and the mandrel; the cordhaving successive sections thereof moved axially generally perpendicularof the plate and transverse of the axis of the mandrel, the axis of thecord being moved transversely of the plate to move portions of the cordadjacent the other end thereof into and through the slot; and meansattached to the plate for engaging ones of the last few convolutions ofthe cord as the other end of the cord is unwound from the mandrel andfor retaining the last Few convolutions of the cord on the mandrel-sideof the plate to maintain the cord strung between the plate and theholding means.
 14. An apparatus for unwinding and reversing the pitch ofthe helices of a plurality of retractile cords, each of the retractilecords being wound helically on a mandrel, which comprises: a frame;means for mounting rotatably the mandrels on the frame; a carriagemounted reciprocally on the frame; a plurality of spindles rotatablymounted on the carriage, each of the spindles adapted to hold one end ofthe one of the retractile cords, further each of the spindles alignedwith one of the mandrels; means for moving the carriage from an initialposition in a first direction relative to the mandrels to unwind thecords from the associated mandrels; means responsive to the movement ofthe carriage in the first direction for rotating the spindles in a firstrotary direction to reverse the pitch of the helices of the cords andfor overtwisting the cords to form additional helices of the reverseddirection in the coiled portion; a stationary plate attached to theframe and positioned between the means for mounting rotatably themandrels and the carriage, the plate having a plurality slots cuttherein, each of the slots aligned with the axis of an associated one ofthe cords as strung between the spindles and the mandrels; the cordshaving successive sections thereof moved axially generally perpendicularof the plate and transverse of the axis of the associated mandrels, theaxes of the cords being moved transversely of the plate to move portionsof the cords adjacent the other ends thereof into and through theassociated ones of the slots; means attached to the plate for engagingportions of the cords adjacent the other ends thereof as the other endsof the cords are unwound from the associated ones of the mandrels andfor retaining at least few convolutions of the cords on the mandrel-sideof the plate to maintain the cords strung between the plate and theassociated ones of the spindles; means for moving the carriage in asecond direction opposite to the first direction to return the carriageto the initial position; and means responsive to the movement of thecarriage in the second direction for rotating the spindles in a secondrotary direction opposite to the first rotary direction to remove theovertwist from the cords.
 15. An apparatus for unwinding and reversingthe pitch of the helices of a plurality of retractile cords, each of theretractile cords being wound helically on a mandrel, which comprises: aframe; means for mounting rotatably the mandrels on the frame; acarriage mounted reciprocally on the frame; a plurality of spindlesrotatably mounted on the carriage, each of the spindles adapted to holdone end of one of the retractile cords, further each of the spindlesaligned with one of the mandrels; means for moving the carriage from aninitial position in a first direction relative to the mandrels to unwindthe cords from the associated mandrels; means responsive to the movementof the carriage in the first direction for rotating the spindles in afirst rotary direction to reverse the pitch of the helices of the cordsand for overtwisting the cords to form additional helices of thereversed direction in the coiled portion; a stationary plate attached tothe frame and positioned between the means for mounting rotatably themandrels and the carriage, the plate having a plurality of slots cuttherein, each of the slots aligned with the axis of an associated one ofthe cords as strung between the spindles and the mandrels; the cordshaving successive sections thereof moved axially generally perpendicularof the plate and transverse of the axis of the associated mandrels, theaxes of the cords being moved transversely of the plate to move portionsof the cords adjacent the other ends thereof into and through theassociated one of the sloTs; the cords having still further successivesections thereof adjacent the other ends thereof engage the bottom wallsof the associated slots as the trailing end portions are unwound fromthe mandrels to permit the last few convolutions to expand to anoriginal diameter; a plurality of pairs of pins attached to the plateand extending laterally therefrom toward the means for mounting themandrels, each pair of the pins associated with one of the slots, one ofeach pair of the pins being on one side of the associated slot and theother one of the pair on the other side of the associated slot, furthereach pair of the pins being spaced above the bottom of the associatedslot; each pair of the pins engaging portions of the cords adjacent theother ends thereof after the last few convolutions thereof have expandedon the mandrel side of the plate for retaining the last few convolutionsof the cords on the mandrel-side of the plate to maintain the cordsstrung between the plate and the associated ones of the spindles; meansfor moving the carriage in a second direction opposite to the firstdirection to return the carriage to the initial position; and meansresponsive to the movement of the carriage in the second direction forrotating the spindles in a second rotary direction opposite to the firstrotary direction to remove the overtwist from the cords.